TY - JOUR

T1 - Metallurgical aspects of joining commercially pure titanium to Ti-6Al-4V alloy in a T-joint configuration by laser beam welding

AU - Fomin, Fedor

AU - Frönd, Martin

AU - Ventzke, Volker

AU - Alvarez, Pedro

AU - Bauer, Stefan

AU - Kashaev, Nikolai

PY - 2018/7/1

Y1 - 2018/7/1

N2 - The present paper focuses on the metallurgical and microstructural characterization of the laser beam-welded T-joints between commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy. The weld regions were comprehensively studied and the mechanisms leading to the final morphology within each weld region were described. The link between microstructural features and local mechanical properties was demonstrated. Owing to different constitution, the responses of the two titanium alloys to thermal cycles imposed by laser welding are completely different. A strong interface with no dilution zone between the two alloys was observed. The cooling rate during the welding process is high enough for diffusionless martensitic transformation in the Ti-6Al-4V part of the fusion zone. In contrast, no evidence of martensite was found in the CP-Ti because of low solute content and, consequently, much higher critical cooling rate. Plausible reason for some controversy found in the literature on the resulting transformation products after laser processing of CP-Ti was given. The present findings might have important industrial implications because careful microstructural characterization revealed the real position of the skin fusion line, which is of great importance for fulfillment of the weld quality criteria. [Figure not available: see fulltext.].

AB - The present paper focuses on the metallurgical and microstructural characterization of the laser beam-welded T-joints between commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy. The weld regions were comprehensively studied and the mechanisms leading to the final morphology within each weld region were described. The link between microstructural features and local mechanical properties was demonstrated. Owing to different constitution, the responses of the two titanium alloys to thermal cycles imposed by laser welding are completely different. A strong interface with no dilution zone between the two alloys was observed. The cooling rate during the welding process is high enough for diffusionless martensitic transformation in the Ti-6Al-4V part of the fusion zone. In contrast, no evidence of martensite was found in the CP-Ti because of low solute content and, consequently, much higher critical cooling rate. Plausible reason for some controversy found in the literature on the resulting transformation products after laser processing of CP-Ti was given. The present findings might have important industrial implications because careful microstructural characterization revealed the real position of the skin fusion line, which is of great importance for fulfillment of the weld quality criteria. [Figure not available: see fulltext.].

KW - Engineering

KW - Laser welding

KW - EBSD

KW - Laser beam welding

KW - Microstructure

KW - T-Joint

KW - Titanium alloys

KW - EBSD

KW - Laser beam welding

KW - Microstructure

KW - T-joint

KW - Titanium alloys

UR - http://www.scopus.com/inward/record.url?scp=85046468618&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/5235aee1-ada5-3e07-b4be-795ad73fc1cb/

U2 - 10.1007/s00170-018-1968-z

DO - 10.1007/s00170-018-1968-z

M3 - Journal articles

VL - 97

SP - 2019

EP - 2031

JO - The International Journal of Advanced Manufacturing Technology

JF - The International Journal of Advanced Manufacturing Technology

SN - 0268-3768

IS - 5-8

ER -